Using routers as displays

Have you ever seen an LED display made out of routers? [Sean] took eight Netgear routers and made an 8×4 display out of them. Because that wasn’t cool enough, a very small version of Conway’s Game of Life was added to the build.

Each router is running a copy of OpenWrt, a Linux distro meant for limited hardware. Instead of an 802.11 protocol, each router runs the B.A.T.M.A.N. advanced mesh protocol. This protocol allows each router to communicate with all the other routers.

Instead of each router receiving data from a master, the routers calculate each step in the Game of Life independently. Once the routers communicate their initial states, each router is responsible for displaying its four LEDs for each new generation. In the video after the break, you can see [Sean]’s routers calculating random Game of Life boards. Sadly, we didn’t notice a GoL oscillator being randomly generated, but with a 4×8 play field even a Glider wouldn’t last very long.

Any cluster of easily obtainable & low cost computers is cool. Making it do something is more cool. I think think the next step should be some parallel processing. Folding@home for the HAD team would be good one.

Have I ever seen a video display made out of routers? Yes… well, they were managed switches and it was at Interop 2007.

I spoke to their engineers about it; apparently they noticed that you can force a packet to be delivered to a VLAN on a particular port, even if no cable is attached. From there, it was just a matter of making it bigger.